1. Field of Invention
Embodiments of this invention relate in general to layer-2 (L2) resources of network devices. More specifically, embodiments of this invention relate to methods and systems for tracking L2 resources of network devices.
2. Description of the Background Art
In computer networks, data is transferred through a series of hardware and software levels or layers. These layers may be broadly classified into a network interface layer, an inter-network layer, a transport layer, and application layer. The network interface layer includes a physical layer and a data-link layer. The physical layer relates to the electrical and mechanical connections between the network devices. The data-link layer is layer-2 (L2) in an Open Systems Interconnect (OSI) model and controls the transfer of data across the physical layer in the computer network. The data-link layer (hereinafter referred to as the L2 layer) is further divided into a Logical Link Control (LLC) layer and a Media Access Control (MAC) layer. The MAC layer controls the access of network components to the data that is being transferred. In order to control the access of the network components, the MAC layer defines an L2 resource for each network device. The L2 resource can be defined by using a unique hardware/data-link/MAC address for each network device. The data is transferred within the computer network, based on the destination MAC address.
Network devices such as switches maintain a MAC-address-table in which the MAC address of each computer connected to the respective network devices is stored.
In conventional switches, the state of the MAC addresses in the MAC-address-table may be determined by using an Internetworking Operating System (IOS) Command Line Interface (CLI) entry such as a ‘show MAC-address-table’. Further, the changes in the state of the MAC address are logged in conventional switches.
However, conventional switches do not monitor L2 features that direct a change in the state of the MAC address. The L2 features that may direct the change in the state of the MAC address may be, for example, distributed forwarding, distributed learning and MAC limiting. Further, conventional switches do not monitor other L2 resources such as a Virtual Local Area Network (VLAN) identifier.